In a conventional independent rear suspension system for an automotive vehicle, each rear wheel is mounted independently of the other, i.e., there is no common rear axle. Each rear wheel is rotatably mounted on a wheel spindle which is, in turn, fixedly bolted to the lower end of an elongate, generally vertically extending shock strut. The upper end of the shock strut is attached to a body side panel, typically by a rubber insulated top mount assembly with attachment bolts. Due to the length and resiliency of the shock strut, the spindle and attached tire are, to a small degree, displaceable in a direction perpendicular to the longitudinal axis of the shock strut and are also torsionally (twistably) displaceable about this axis if otherwise unrestrained. In order to restrain this movement and hold the wheel in a fixed orientation with respect to the vehicle frame, there is provided a control arm comprising a central portion affixed to the spindle and outwardly oppositely extending ends, each end being affixed to a bracket secured to the vehicle frame. Due to manufacturing tolerances etc. in the rear wheel assembly, the "toe" and "camber" of a rear wheel in some cases needs adjustment.
The control arm, which determines the lateral position of the forward and rear portions of the spindle and thus the toe of the associated wheel and the vertical position of the top and bottom portion of the spindle and thus the camber of the associated wheel are provided with bushings at either end thereof for accepting a bolt to attach each end to a bracket secured to the vehicle frame. The attachment hole portions in the spindle and the bracket on the vehicle frame are of approximately the same diameter as the attachment bolts. The only method of adjusting the toe of a tire in such an arrangement is provided by the "slop" between the bolt receiving holes in the control arm frame and spindle and the diameter of the corresponding attachment bolts. To make toe and camber adjustments in such an assembly, the attachment bolts at the ends of a control arm are loosened while the vehicle is supported on toe and camber adjustment plates. Thereafter, one mechanic moves the wheel laterally to a desired toe or camber position to the extend possible and another mechanic retightens the bolts. A problem with this solution is that due to vibration etc. of the vehicle during ordinary use, the toe and camber of the vehicle may shift because of lack of positive lateral restraint between the bolts, control arm and the attachment portions of the frame and spindle. Another problem with such an adjustment procedure is that only a relatively small amount of toe or camber adjustment is possible since the amount of "slop" between the bolts and associated holes is usually relatively small. Yet another problem with such an adjustment procedure is that it requires the service of two mechanics. One prior art device uses cams which are mounted in built up bosses.